Grounding rings are used to suppress electrical interference at the installation location for electromagnetic flow meters. They are sold in pairs and are installed upstream and downstream of the flow meter. Use of grounding rings significantly reduces electrical noise and may be necessary for proper operation of electromagnetic flow meters installed in lined or non-conductive pipes.
The size of the grounding rings should always match the meter size (as opposed to the original pipe size) for installation with in-line meters. Standard grounding rings are for use with ANSI Class 150 flanges and are made of 316 stainless steel.